1. Field of the Invention
This invention relates to a process for preparing coal suspensions which comprises contacting coal with nitric acid and then combining said contacted coal with an aqueous base solution.
2. Description of the Prior Art
In our U.S. Pat. No. 4,261,701, dated Apr. 14, 1981, we have disclosed (I) a suspension containing (1) coal, (2) water and (3) the product resulting from the reaction of (a) polycyclic, polycarboxylic acids obtained as a result of the oxidation of coal with (b) a base and (II) a process for preparing such suspension. In the process defined in said patent, we mixed (A) an aqueous mixture containing (1) the product resulting from the reaction of (a) polycyclic, polycarboxylic acids obtained as a result of the oxidation of coal with (b) a base with (B) coal.